Coherent and/or polarized light is required for a plethora of optical applications such as optical signal processing in communications, optical characterization and like fields. The requirements for light of a specific, predetermined polarity has led to the development of polarizers of various types.
Unexamined Japanese Application No. 164048 discloses a polarizer of the birefringent diffraction grating type employing a lithium niobate substrate and periodic array of proton exchanged regions.
Unexamined Japanese Application No. 162221 discloses a waveguiding polarizer including a refractive index distribution wherein the polarizer portion of the guide is fabricated by way of proton exchange to achieve index differences. A variety of other similar devices may be fabricated in inorganic substances as is taught in Japanese Patent applications 000902 and 300727 (unexamined).